Battery Turn Around

I read once that you can prevent accidental discharge of batteries in a long time storage situation by turning one of the batteries around. So in a 2 cell light, both the negative ends would be together. Has anyone else heard this? This would work for my lights with tac switch, but no lock out. But I don't know if this will hurt Lithiums.

Practically speaking, it will not work. In the case of a two cell system, you would be putting the cells in parallel when the switch was activated. If the two cells where of the same type and age, you might be O.K. After all, Surefire parallels up three pair of CR123's in the M6.

But if the cells were not relatively close in voltage and internal impedance, the stronger of the two cells would be drained slightly by trying to charge the weaker cell. Naturally, you won't 'see' any of this happening, as the bulb will have 0 volts applied to it.

For systems where you have more than two cells, the voltage applied to the bulb during discharge will be 'N-2', where N=number of cells. If you had a five cell system and reversed one of the cells, the reversed cell would cancel one cell, leaving the remainder to power the bulb. (5 minus 2 equals 3)

If you are worried about the switch turning on during a period of long term storage, I would suggest inserting some type of insulator on the last cell. A nylon washer or even a heavy grade of craft paper should do the trick.

My father has been doing this since before I was born...which is a pile of years!

While, as has been pointed out, this is not a good idea for other than two cell lights (unless it's an even number and you reverse half) and dissimilar state cells, it makes excellent sense in some cases IMO. The case cited being one in point.

If you don't mind having to reverse the cell before use (my father automatically starts unscrewing the back of the flashlight when he picks it up....) and want the security, I say go for it.

Doug Owen